Base for electric lamps and the like



.Dec. 14, 1943. p o, CARTUN 2,336,529

BASE FOR ELECTR C LAMPS AND THE LIKE Filed Aug. 27, 1942 2 Sheets-Sheet 1 lnven'tor: Paul O. Car'tun 1 His A ttorneg.

1943- P. o. CARTUN 2,336,529

BASE FOR ELECTRIC LAMPS AND THE LIKE Filed Aug. 27, 1942 2 Sheets-Sheet 2 'lnveWbor: 'PauL O. Car'tun,

His Aiftorney.

Patented Dec. 14, 1943 UNI ED STATES PATENT OFFICE BASE Fort ELECTRIC LAMPS AND THE LIKE Paul 0. Cartun, Cleveland Heights, Ohio, as-

signor to General Electric tion of Ne'w York Company, a corpora-.

Application August 27, 1942, Serial No. 456,351,

'9 Claims.

This invention relatesto basing the bulbs or envelopes of electrical devices, including incanbase comprising a metal skirt in the form of a screw shell III with a button-shaped insulative body II in theiouter end thereof, such as glass,

' hard rubber, molded plastic, or indurated fiber.

The end body I I carries an end or center contact l2. Ordinary basing cement l3 may be used to secure the base shell or skirt I around the neck of an incandescent lamp bulb B in the usual way. As shown in- Fig. 2, the insulative body H is seated against an internal seating shoulder or flange 15 in the shell 10, at the outer side of this shoulder, and is peripherally embraced and of the invention here shown and described, the

base is put together on thesnap fastener-principle. with particular reference to bases of the Edison and kindred. screw and center contact types,

though it is also applicable to bases ofvery different types from this, such as the double end contact bayonet type, for example.

Other features and advantages of the invention will become apparent from the description of species and forms of embodiment,'and from the drawings.

In the drawings, Fig. 1 is a side view of a screw type of base embodying the snap fastener principle according to my invention in one form of construction, a portion of an electric lamp bulb to which the base is applied being also shown;

4 Fig.2 shows an axial section through this base,- with a. portion of the lamp bulb B in side elevationrand Fig. 3 is an exploded view of the principal base parts, the screw shell and insulator being shown tilted one way, while the end contact is oppositely tilted.

Fig. 3A is a tilted'view illustrating a modified form of one of the parts shown in Fig. 3'.

Figs. 4 and 5 are views similar to Figs. 1 and 2 showing a base with a different form of snapfastened end contact from that shown in Figs. 1 to 3; and Fig. 6 is an exploded view similar to Fig. 3, but showing only the insulator and the end contact.

Figs. '7, 8, and 9 are views generally similar to Figs. 1, 2, and 3, but illustrating other modifica- The invention is hereinafter explained gripped by the end portion I6 of they shell, with a snap action. This shell portion I6. and the seat 15 are shown in Figs. 2 and 3 asformed by doubling the sheet metal oi the;.-she1l 10 back thereinto, and flanging its extrememargin. The general conformation of the shell portions l5, l8 resembles that shown'in U. 5. Patent 2,184,269 to Carl A. Brown and'Clarence'E. Hahn; but there is an important difierence: viz., the shell portion i6 here shown does not rigidly and permanently secure the insulator II, but holds it resiliently and yieldingly,"in a manner similar to the snap action of an ordinary glove fastener. This-is made possible by segmentation of the doubled annular flange or ridge |6,by radial slots ll, into a multiplicity of spring :lo'cking fingers 18 that are free to separate in flexing outward. As shown in Fig; 3, the slots l1 'do not extend or cut through the seat flange 15, so that thelatter forms an annular interconnection of the root ends of the inner portions of the spring fingerslii, though thisis not essential. The outer surface of the insulator I1 is shown conically beveled, with a rounded corner at its periphery,

- and the ends of the spring fingers l8 overhang inward somewhat to snap over and grip the insulator'securely when the latter is pushed home to the seat I5.

The connection of a corresponding lamp lead- 20 to the screw shell 10 may be made by simply passing the lead through the shell, when the latter is placed on the neck of the lamp bulb B, and then bending it aside, so that it will be gripped between the shell portion l5 or iii and the insulator II, when the latter is snapped into place,'by the elastic snap action. Afterward, the lead 20 may be cut oil about as shown at 2|. Even if the wire 20 should lie in one of the slots ll, it will still be firmly and elastically pressed a ainst the seat l5 by the snap action.

As shown in Figs. 2 and 3, the end contact I! is snap-fastened into the insulator II, which has a central recess or hole 22 for this purpose, preferably beveled inward from the flat outer end surface of the insulator. The contact I2 may consist of a disc-like head 23 having an internal hollow shank that engages in and around the opening 22, and is slit into a number of spring locking fingers 24 shown with external beveled shoulders at their free lower ends, for snapping outward behind the shoulder of the insulator opening 22 when the contact is pushed home into the opening. The contact l2 may be formed of sheet metal by a die-pressing and drawing operation, the margin of its head 23 being formed by doubling under the sheet metal as shown in F 2.

The connection of a lamp lead 25 to the contact l2 may be made by simply passing the lead through the insulator II when the latter is put in place in the screw shell l and bending it aside, so that it will be gripped between the disc contact l2 and the fiat outer surface of the insulator, when the contact is snapped into place, by the elastic snap action. Afterward, the lead 25 may be cut of! about as indicated at 26. Even if the wire 25 should lie between two of the spring fingers 24, it will still be firmly and elastically gripped against the underside of the disc l2 by the snap action.

Fig. 3A illustrates a modified form of end contact |2A comprising a sheet metal disc head 23A with spring locking fingers 24A, 24A formed by folding under the disc 23A two diametrally opposite strips of the sheet metal of which the disc is made, and also bending these strips downward away from the disc. The fingers 24A, 24A may be stiffened by longitudinally embossing them to conform to the rounded opening 22 of the part II, and may have their ends bent and beveled outward to form shoulders for snapping behind the shoulder of the opening 22. Such a part I2A can be readily fabricated from strip sheet metal by die-punching, bending, and embossing operations.

Figs. 4 to 6 illustrate a different form of end contact l2a, with a correspondingly different snap action. The end contact l2a resembles a cap or an inverted sauce dish with its wall somewhat undercut, and divided by slits into a multitude of spring locking fingers 28, while the top corner of the insulator II a is rounded and annularly undercut so that these fingers can snap over the resulting button-like head 29, Figs. and 6, around the opening in the insulator. The connection of the lamp lead 25a to the contact lZa may be essentially like that of lead 25 to contact l2, Figs. 1 to 3.

Both of these constructions allow the parts l2 or I24! and II or Ila to be readily detached from one another and from the part 10.

Figs. 7, 8, and 9 illustrate a variation in the snap connection of the insulator to the screw shell. Here the insulation lib has a stop shoulder l5b that abuts and seats against the end portion I 622 of the screw shell "lb, and a reduced portion 30 that enters amongst the many spring locking fingers [8b into which the inturned sheet metal shell end is divided. The ends of these spring fingers l8b are not shown annularly interconnected as in Figs. 1 to 6, but free for independent elastic fiexure. The reduced insulator portion 30 is itself reductively shouldered at 3| for latching snap engagement with the ends of the spring fingers no In the present instance, the locking shoulder feature 3| does not extend continuously all around the insulator portion 30, but is localized at a plurality of notches 32 sliced" into the periphery of the portion 30, three such notches being shown. The engagement of the ends of a few spring fingers l8b against the shoulder 3| afforded by each notch 32 sufiices to hold the insulator llb securely.

As shown in Figs. 7, 8, and 9, the center contact H1) is not snap fastened, but consists of a mere cap whose annular wall is wedged fast in a corresponding annular groove 33 in the insulator Ilb, as shown in Patent No. 2,047,043, granted July 7, 1936, to R. F. Strickland, and in Patent No. 2,066,317, granted January 5, 1937, to H. D. Blake and W. J. Geiger. The lamp leads 20, 25 may be secured and connected to the screw shell lllb and center contact I2b as illustrated in Fig. 2 and in the said Patent No. 2,047,043. respectively.

Figs. 10, 11, and 12 illustrate another variation in the snap connection of the insulator to the screw shell. Instead of having its-portion I6c slit up into a multitude of spring fingers, this portion is a plain annular wall broken only by the punching out of a few isolated spring fingers I80 (three being shown) whose free lower ends are bent inward to snap into corresponding bevelshouldered notches 320 in the insulator l to when the latter is put in place and pushed home. As shown in Fig. 10, the center contact He is not snap-fastened like those in Figs. 1 to 6, but is a mere eyelet with flared end 35 molded into the insulation Hcas usual in lamp bases, and connection of the corresponding lead 25 to this contact He may be made by soldering or welding after the lead has been passed through the contact.

' However, it will be understood that other forms of end contact might be used with the insulator I I0, such as snap-on types like those of Figs. 1 to 6, for instance.

Fig. 13 shows an insulator ll like that in Figs. 1-3 and a. center contact somewhat resembling the contact I20 in Figs. 10-12, consisting of an eyelet or tubular rivet l2d having a flat outer flange or head, and inserted in the fiaring center hole 22 of the insulator and having its inner end expanded to a flaring inner flange or head 35d that secures it in place. The eyelet or rivet l2d may be put in after the insulator II has been snapped into the screw shell I0 already cemented on the lamp bulb B, Figs. 1 and 2, and may then be flanged at 35d by means of a suitable instrument inserted through the eyelet or rivet. Instead of extending through the eyelet or rivet as in Fig. 11, the lead wire 25 is passed through the insulator opening 22 before the rivet I2d is put in place, and is clamped between the outer rivet head and the top surf ace of the insulator l l essentially a in Fig. 2, besides being wedged between the conical surface of the insulator and the corresponding surface of the rivet shank. The wire 25 is finally cut off at 26d close to the edge of the outer rivet head, essentially as in Fig. 2.

. Throughout the drawings, homologous parts are marked with the same reference numerals in order to dispense with repetitive description, distinctive letters being added where such distinction of modified parts appears necessary,

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a base construction for electric lamps and similar devices, the combination with a metal shell having its outer end closed by a buttonshaped base end insulator having an apertured engagement part, of a base end contact havin a snap fastener for snap interlock with said engagement part.

2. In a base construction for electric lamps and similar devices, the combination with a buttonshaped base end insulator, of a metal base shell having a snap fastener at its outer end for embracing snap interlock with the periphery of said insulator.

3. In a base construction for electric lamps and similar devices, the combination with an apertured button-shaped base insulator, of a base shell having a snap fastener at its outer end for embracing snap interlock with the periphery of said insulator, and an end contact having a snap fastener for snap interlock around the aperture in said insulator.

4. In a base construction for electric lamps and similar devices, the combinationwith an apertured button-shaped base insulator, of an end contact having a snap fastener for snap interlock around the aperture in said insulator, and a base shell having an internal seat for said insulator at its outer end and superjacent snap fastener means for embracing snap interlock with the periphery of said insulator.

5. In a base construction for electric lamps and similar devices, the combination with an apertured button-shaped base insulator, of an end contact having a snap fastener for snap interlock around the aperture in said insulator, and a base shell having at its outer end a series of internal resilient locking fingers for embracing snap interlock with the periphery of said insulator, and seating means for said insulator carried by the inner ends of said locking fingers.

6. In a base construction for electric lamps and similar devices, the combination with an apertured button-shaped base insulator, of an end contact having a snap fastener for snap interlock around the aperture in said insulator, and a base shell having it outer end doubled inward and flanged to fit around and seat the periphery of said insulator, and slit to give the doubled portion resilience for snap interlock on aid insulator periphery.

7. In an electric lamp comprising a bulb having a neck portion with lead wires extending therefrom, a base comprising a cylindrical metal shell with its inner end circumposed about and secured to the neck of the bulb and having snap fastener means at its outer end, and a buttonshaped insulator secured to the said outer end of the shell bya snap interlock engagement of its periphery with the said snap fastener means, one of said lead wires being clamped between aid insulator and said outer end of the shell.

8. In an electric lamp comprising a bulb having a neck portion with lead wires extending therefrom, a base comprising a cylindrical metal shell with its inner end circumposed about and secured to the neck of the bulb and having its outer end retroverted with snap fastener means formed in said retroverted outer end, and a button-shaped insulator secured to the said-outer end of the shell by a snap interlock engagement of its periphery with the said snap fastener means, one of said lead wires being clamped between said insulator and said outer end of the shell.

9. In an electric lamp comprising a bulb having a neck portion with lead wires extending therefrom, a base comprising a cylindrical metal shell with its inner end circumposed about and secured to the neck of the bulb and having snap fastener means at its outer end, and an apertured button-shaped insulator secured to the said outer end of the shell by a snap interlock engagement of its periphery with the said snap fastener means, one of said lead wires being clamped between said insulator and said outer end of the shell, and a metal end contact having snap fastener means formed therein and secured around the aperture in the said insulator by a snap interlock engagement with the insulator, another lead wire being clamped between the said end contact and a portion of the insulator.

PAUL O. CARTUN. 

